Hydraulic briquetting press



Nov. 3, 1964 J. HALLER HYDRAULIC BRIQUETTING PRESS 6 Sheets-Sheet 1 Filed March 7, 1962 INVENT JOHN HALLE Y mwww ATTORNEYS t l-i764 Iss1 I q Nov. 3, 1964 J. HALLER 3,154,812

HYDRAULIC BRIQUETTING PRESS Filed March 7, 1962 6 Sheets-Sheet 2 FIG.2

INVENTOR.

JOHN HALLER BY 6M6) FIG- IO ATTORNEYS 6 Sheets-Sheet 4 Filed March 7, 1962 FIG.5

INVENTOR. JOHN HALLER Kimm ATTORNEYAS Nov. 3, 1964 J. HALLER 3,154,812

HYDRAULIC BRIQUETTING PRESS Filed March 7, 1962 6 Sheets-Sheet 5 FIGB INVENTOR.

JOHN HALLER M ATTORNEYS Nov. 3, 1964 Filed March '7, 1962 J. HALLER HYDRAULIC BRIQUETTING PRESS 6 Sheets-Sheet 6 FIG-9 INVENTOR.

JOHN HALLER WY/JW ATTORNEYS United States Patent 3,154,812 HYDRAULIC BRIQUETTING PRESS John Haller, 18500 Sheldon Road, Northville, Mich. Filed Mar. 7, 1962, Ser. No. 178,055 11 Claims. (Cl. 1816.'7)

This invention relates to hydraulic presses and, in particular, to hydraulic bn'quetting presses.

Hitherto, workers in the field of powder metallurgy and other fields involving the production of shouldered or flanged workpieces from metallic or non-metallic powder have found it difiicult to produce such workpieces because of the formation of cracks between the flange or shoulder and the thicker body portion of the workpiece. These cracks and consequent breakage arise from the didiculty of ejecting all portions of the workpiece without developing relative motion between the thin flange or shoulder portion [and the thicker body portion or hub of the workpiece. W orkpieces in which this problem of cracking or breakagehas arisen include thin discs with thicker central hubs or with thickened marginal flanges, as well as wheels in the form of cams, sprockets or gears having axially thicker hubs than peripheries and in genenal, workpieces having sudden and considerable differences in axial thickness existing between adjacent portions thereof.

The present invention solves this problem by providing a hydraulic briquetting press constructed and arranged to eject the finished flanged workpiece of compressed powdered material by so-called forward stripping wherein all portions of the workpiece move out of the die cavity at a uniform speed, both the hub and the flange being moved at precisely the sarne speed until the periphery of the flange emerges from land clears the die cavity.

Accordingly one object of the present invention is to provide a hydraulic briquetting press for pressing, from metallic or non-metallic powdered materials, workpieces such as briquettes wmch have axially thick portions bordering upon axially thin portions, such as a wheel or disc having an axially thick hub with an axially thin periphery, ejection being accomplished by moving the shoulder punch and bottom punch simultaneously at a uniform speed and in an even manner, to effect forward stripping of the workpiece from the die cavity.

Another object is to provide a hydraulic briquetting press of the foregoing character having a vertically-movable die table which is mounted on and moved by hydraulic pistons, its upward motion being adjustably limited by stop members which in turn engage wedgeoperated adjustable abutments whereby the vertical travel of the die table can be quickly and accurately regulated.

Another object is to provide a hydraulic briquetting press of the fore oing character wherein the die set is provided with a lower punch or bottom punch which engages the bottom of the thickened portion or hub of the workpiece and forms the bottom of the inner or central portion of the die cavity, this lower or bottom punch being moved vertically by a lower ram or hydraulic piston, the extent of vertical travel of which is precisely limited by a quickly and easily adjustable stop mechanism.

Another object is to provide a hydraulic briquetting press of the foregoing character wherein the die set is also provided with a tubular outer lower punch or shoulder punch which forms the outer portion of the bottom of the die cavity and, in cooperation with the upper punch, forms the flanged portion of the workpiece, this outer lower punch being also mounted on and moved vertically by means of hydraulic pistons in such a manner as to enable it to rise to the level of the upper surface of the die and thereby, in cooperation with the inner lower punch, eject the workpiece from the die cavity.

3,154,812 Patented Nov. 3, 1964 Other objects and advantages of the invention will become apparent during the course of the following description of the accompanying drawings, wherein:

FIGURE 1 is a diagrammatic front elevation, mainly in central vertical section, of a hydraulic briquetting press for the production of flanged or shouldered workpieces, according to one form of the invention, showing the relative positions of the moving parts at the end of a pressing cycle, ready for expulsion of the workpiece after ejection from the die cavity and consequently ready for the commencement of the next filling and pressing cycle;

FIGURE 2 is a fnagmentary central vertical section taken at right angles to the section plane of FIGURE 1, showing the powdered material feed box in its retracted position ready to move forward and expel the ejected workpiece and at the same time move into position for subsequent filling of the die cavity with powdered material for the start of the next pressing cycle;

FIGURE 3 is a view similar to FIGURE 2, but showing the feed box moved to its forward position over the die after having expelled the previously-formed workniece;

FIGURE 4 is a view similar to FIGURES 2 and 3, showing the formation and filling of the die cavity with powdered material in response to the descent of the lower outer and inner punches;

FIGURE 5 is a view similar to FIGURE 1, but showing the relative positions of the parts of the press with the die cavity filled with powdered material and the feed box retracted from its forward position of FIGURE 4 to its rearward position of FIGURE 2, ready for the descent of the upper punch to perform the pressing operation;

FIGURE 6 is a view similar to FIGURE 5, but showing the relative positions of the moving parts or" the press with the upper punch within the die cavity at the termination of its pressing stroke;

FIG ME 7 (on Sheet 3) is a fragmentary central vertical section through the die set and its adjacent parts in their relative positions of FIGURE 6, but with the upper punch retracted from the die cavity and with the die table and outer lower punch moved upward;

FIGURE 8 (on Sheet 3) is a view similar to 7, but showing the lower inner punch and lower outer punch pistons again moved upward into contact with workpiece bottom surfaces of hub and flange respectively;

FIGURE 9 is a central vertical section through the press of FIGURES l to 8 inclusive but showing the flange portion of the workpiece ejected by further upward motion of the lower inner and outer punches, ready for the final ejection of FIGURE 1.

FIGURE 10 is a fragmentary top plan view of the cross shaft and gearing interconnecting the screw-threaded stop shafts on the upper press frame, looking in the direction of the arrow 10 in FIGURE 2.

Press Frame Construction Referring to the drawings in detail, FIGURE 1 shows, somewhat diagrammatically to simplify the disclosure, a hydraulic briquetting press, generally designated 10, according to one form of the invention, with the relative positions of its moving parts shown at the end of one operating cycle which has produced a finished workpiece in the form of a compact or briquette of powdered material, either metallic or non-metallic (such as nylon or other synthetic plastic material) with the workpiece ready to be expelled, after which the press is ready for the beginning of the next operating cycle. The workpiece W made by the press is shown as exemplary but not by way of limitation, since the proportions and arrangements of the various portions may be altered to suit the particular job. The workpiece W shown in FIGURE 1, consists of a central axially-thickened portion or hub a ,3 H at the top of which is a relatively thin annular peripheral flange F which surrounds the central portion or hub H. The press is adapted to produce workpieces W of compressed powdered material without the cracking or breakage which frequently occurs in prior presses at the junction I between the flange F and hub H of the workpiece W, by the construction and mode of operation explained more fully below. 7

The press 10 is provided with a press frame, generally designated 12, which in turn includes a rectangular bed 14 adapted to rest upon a concrete foundation (not shown), preferably at a level slightly below the floor level, in order to bring the workpiece W in its ejected position (FIGURE 1) at the arm level of an operator of ordinary height. Secured to the press bed 14 and rising from its four corners are four strain rods 16 which at their upper ends enter and are secured to a press head 18. In the ordinary construction of such presses, the upper and lower ends of the strain. rods 16 are provided with slightly reduced diameter shouldered and threaded end portions with the shoulders abutting the press bed 14 and head 18 respectively and with the outer ends of the threaded portions carrying large internallythreaded nuts which are tightened against the outer portions of the bed 14 and head 18 respectively, the outer portionsbeing the lower side of the bed 14 and upper side of the head 18 respectively. These details of construction are conventional and have been omitted to avoid unduly complicating the disclosure.

The press head 18 normally serves as a platform and enclosure to support and contain the hydraulic fluid pres sure supply and operating circuit of the press 10 including a motor-driven hydraulic pump, hydraulic fluid reservoir for the working fluid, generally oil, and the necessary valves, electrical control switches and other equipment and components conventionally present in such hydraulic press-operating circuits. Such hydraulic pressure fluid operating circuits and such components are well known to hydraulic engineers and are available upon the open market, hence these components of the circuit, apart from the hydraulic devices shown in the present drawings, are beyond the scope of the present invention and are believed to require no detailed description.

Press Head and Upper Pressing Mechanism Construction The press head 18, in addition tothe major portion of the electro-hydraulic circuit and its components mentioned above, is provided in its central portion with an upper pressing cylinder 20 containing a cylinder bore 22, the axis of which is disposed on the main vertical central axis 23 of the press 10, approximately equidistant from the centers or axes of, the strain rods 16. Reciprocably mounted in the upper cylinder bore 22 is an upper hollow piston 24 which with the cylinder 20 constitutes an upper reciprocatory hydraulic pressing motor. The piston 24 has a piston head 26 and a hollow piston rod 28, the open lower end'of which is closed by a flanged gland or annular plug 30 bolted or otherwise secured to the lower end of the hollow piston rod 28. The plug 30 is provided with an internally-threaded central bore 32 in which is rotatably mounted in a correspondingly cylindrical recess.

or socket 38 in the central portion 40 of an upper ram, generally designated 42. i

The upper ram 42 has radial arms 44 extending laterally from the central portion 40 and terminating at their outer ends in vertical bores 46 for a purpose explained shortly below. The arms 44 intermediate the central portion 40 of the ram 42 and the outer end bore 46 pass through slots or gaps 48 in or between approximately L-shaped upper ram piston stops 50 depending from an annular flanged support 52 bolted or otherwise secured to the lower side 54 of the pre s h pp r ram piston stops 50 have inwardly-projecting stop shoulders 56 thereon adapted to engage the lower end 58 of the hollow piston rod 28 of the piston head 26. The head 36 of the screw 34 is retained in its recess 38 by a retaining ring 60 bolted or otherwise secured to the upper side of the upper ram 42. Secured to the central portion 40 of the upper ram 42 is the flange 64 of a flanged upper punch 62 having a lower pressing portion 66 and a central bore 68.

Die Table and Its Adjustable Stop Construction Secured to and depending from the press head 18 near the four corners thereof are two pairs of aligned bearing blocks 70 (FIGURES 1 and 2), each pair of bearing blocks 70 being aligned with an intermediate bored'bearing block 72 (FIGURE 2) also secured to and depending from the press head 18. Rotatably mounted in each set of bearing blocks 70 and 72 are two oppositelythreaded interconnected coaxial screw shafts 74 and 76 which collectively constitute two parallel stop shafts 78 geared together for simultaneous rotation. Driving-1y secured to the outer end of one of the stop shafts 78 (FIG- URE 2) is a hand crank 80, and similarly secured (FIG- URE 10) to the forward end of each stopshaft 78 is a bevel gear 77 meshing with a bevel gear 79 similarly secured to the adjacent end of a cross shaft 81 rotatably mounted in brackets 83 projecting forwardly from the press head 18. Threadedly mounted upon the oppositelythreaded portions 74 and 76 of each stop shaft 78 are two horizontally-movable internally-threaded stop-operating wedge nuts or blocks 82 and 84 (FIGURE 2) facing in opposite directions and having oppositely-inclined wedge surfaces 86 and 88. Engageable with the inclined surfaces 86 and 88 of the two wedge blocks or nuts 82 and 84 are two vertically-movable stop blocks 90 and 92 of approximately U-shaped cross section (FIGURE 1) inclinedly-gr'ooved corresponding to the oppositely-facing stop-operating wedge blocks 82 and 84 and their oppositely-inclined bottom surfaces 86, and 88 and bored and counterbored vertically to receive retaining screws 94 which are threaded into the press head 18. The retaining screws 94 loosely and slidably engage the stop' blocks 90 and 92 in such a manner as to permit rise and fall thereof. The stop blocks 90 and 92 (FIGURES l and 2) are spaced downwardly from the lower side 54 of the press head 18 so as to permit such rise and fall; helical compression springs 96 are disposed on the shanks of the screws 94 between the stop blocks 90, 92 and the press head lower surface 54 (FIGURE 1) to constantly urge the stop blocks 90 and 92 downwardly away from the press head 18. As a consequence, rotation of the stop shafts 78 causesthe stop-operating wedge nuts 82 and 84 to move simultaneously toward or away from one another and consequently changing the locations on-the inclined bottom surfaces 86 thereof at which the stop blocks 90 and 92 will come to rest whenrforced upward against them by the upwardly-moving upper ends of four die table stop rods 98 passing through the vertical bores 46 in the outer ends of the arms 44 of the upper ram 42.

The flanged lower ends of the upstanding die table stop rods 98 are secured to the upper side or surface 99 of a die table, generally designated 100, also of approximately rectangular shape when seen in top plan view and having at its four corners arcuately-machined contact shoes 102 (FIGURE 1) slidably engaging the press frame strain rods 16 asthe die table moves up and down. The die table 100 on its lower side is provided with four equally-spaced threaded sockets 104 (two only being shown) into which are threaded the reduced diameter threaded upper end portions of the piston rods 106 of die table pistons 108 having piston heads 110 reciprocably mounted in four correspondingly-located die table piston cylinders 112 which with the pistons 108 constitute reciprocatory die table supporting motors mounted near the four corners, of a stationary rectangular base plate 114. The base plate 114 near its four corners is mounted upon and secured to upstanding struts 116, the lower ends of which rest upon and are secured to supporting blocks 118 which in turn are secured to and rest upon the enlarged upper end of a main lower cylinder 122 having a vertical cylinder bore 124 coaxial with the upper cylinder bore 22 and main vertical axis 23 of the press 10.

Resting upon and bolted or otherwise secured to the top of the base plate 114 is a flanged internally-threaded base ring 126 into which is threaded an externallythreaded sleeve 128. The upper end of the threaded sleeve 128 is rabbetted or stepped to receive the correspondingly-stepped lower end of an adjustable die table lower stop ring 130, the upper end 132 of which is adapted under the circumstances explained below in connection with the operation of the invention to engage the annular lower end surfaces 134 of an annularly-fianged cylindrical cup-shaped die holder or die pot 136.

Die and Lower Punch Construction The die table 1% is bored and counterbored as at 138 (FIGURE 1) corresponding to the flanged or stepped side walls of the cup-shaped die holder 136 to snugly but removably receive the die holder or die pot 136. The die holder or die pot 135 is in turn bored and counterbored as at 141 to receive the correspondingly-stepped annular die 142 having an upper surface 144 level or flush with the upper surface 99 of the die table 109. The die 142 is provided with a central bore 146 (FIGURE 1) coaxial with the upper and lower main cylinder bores 22 and 124 and serving as the side wall of the stepped annular die cavity 148 (FIGURES 4, 7 and 8). Snugly but slidably mounted in the die bore 146 is a flanged tubular outer lower punch or shoulder punch 150 having a top surface 152 which normally forms the outer bottom surface or shoulder of the die cavity 148 when in a pressing (FIG- URE 4).

The outer lower punch 156 in turn is provided with a central bore 154 which normally forms the side wall of the inner portion of the die cavity 148 (FIGURE 4) and which serves to snugly but slidably receive a verticallymovable tubular inner lower punch 156. The latter has an annular upper surface 153 which normally forms the inner bottom surface of the die cavity 148 in the same manner as the upper annular surface 152 forms the outer bottom surface of the die cavity 143. The lower inner punch 156 is bored centrally and coaxially with the upper and lower main cylinder bores 22 and 124 and main central axis 23 of the press as at 161 (FIGURE 1) to slidably receive a stationary core rod 162 having a reduced diameter threaded lower end mounted in a correspondingly-threaded socket 164 in the center of the base plate 114. The core rod 162 has an upper end surface 166 which in the filling position of the die cavity 148 (FIGURE 4) and in the ejection position of the finished workpiece W (FIGURE 1) is level with the upper surfaces 99, 144, 152 and 158 of the die table 180, die 142, outer lower punch 150 and inner lower punch 156 respectively, but during pressing may temporar'ly occupy a higher position (FIGURE 6).

Die Cavity Filling and Workpiece-Expelling Mechanism The die cavity 148 (FIGURE 4) is filled with powdered material, such as powdered metal, powdered metal alloys or powdered non-metallic material, such as the polyamide synthetic resin known commercially as nylon, by a charging device, generally designated 17% (FIGURE 2) mounted on the upper surface 99 of the die table 100 and slidable therealong between the retracted position of FIG- URE 2, the workpiece-expelling position of FIGURE 3, and the die cavity charging or filling position of FIGURE 4. The charging device 170 includes a rotary hydraulic or pneumatic motor 172 having a rotary shaft 174 (FIG- URE 2) upon which is mounted a pinion 176 meshing with an elongated toothed rack bar 178. Bolted or otherwise secured to the forward end of the rack bar 178 is a charging or filling box or shoe, generally designated 180.

The filling box 180 (FIGURE 3) has vertical tubular upper and lower portions 182 and 186 interconnected by a tubular inclined portion 184. The lower end surface 188 of the lower tubular portion 185 rests upon and slidably engages the upper surface 99 of the die table 1130. The charging box or shoe 180 is supported in part by a vertical prop or leg 191), the lower or bottom surface 192 of which is disposed on the same level as the bottom surface 188 of the lower vertical portion 186 of the charg ing shoe so as to slidably engage the upper surface 99 of the die table 101 Lower Punch Operating and Adjusting Mechanism Reciprocably mounted in the cylinder bore 124 of the lower main cylinder 122 (FIGURE 1) is the piston head 194 of a hollow main piston 196 having an internallythreaded tubular piston rod 193 and with the lower main cylinder 122 constituting a lower main reciprocatory hydraulic motor. Threaded into the threaded bore 2110 of the hollow main piston rod 198 is the correspondinglythreaded hollow flanged screw post 2112, the head of which is externally toothed as at 204. Meshing with the toothed head 204 (FIGURE 1) is an elongated pinion 206 along which the toothed head 204 may slide longitudinally while being rotated by the intermeshing teeth thereof. The reduced diameter lower end of the elongated pinion 266 is journaled in a bearing block 2198 while on the reduced diameter upper end portion 210 is mounted a worm wheel 212. Meshing with the worm wheel 212 is a worm 214 on the inner end of a worm shaft 216 journaled in a horizontal bore 218 in the base plate 114. Operatively connected to the outer end of the worm shaft 216 is a hand crank 220 for adjustment purposes. When the hand crank 2'20 and worm shaft 216 are rotated to rotate the elongated pinion 20 6, the consequent rotation of the toothed head 2114 of the screw post 202 causes the latter to move upward or downward within the threaded bore 290 to raise or lower a so-called lower ram 226 (FIG- URE l).

Stationarily mounted on top of the toothed head 204 of the screw post 262 within the hollow piston rod 2% of the lower main piston 196 is the enlarged or flanged lower end portion 222 of the lower end wall 224 of the hollow lower ram 226, relative rotation being efiected between the lower main ram 226 and the screw post 2132 by a pivot pin or bolt 228 (FIGURE 1) passing through the bottom wall 224 and head 2134 coaxially with the upper and lower main cylinder bores 22 and 124 and bearings 230 and 232 disposed therebetween. The lower main ram 226 has vertically-elongated horizontal slots 234 permitting the ram 226 to move upward or downward while clearing the stationary base plate 114, which passes horizontally through the slots 234. The central portion of the lower main ram 226 is hollow as at 236 for the passage of the core rod 162 attached to the base plate 114. Resting upon and bolted or otherwise secured to the upper end wall 238 of the lower main ram 226 is a circular cylinder block 241 containing four cylinder bores 242 (two only being shown) arranged symmetrically about the main central axis 23.

Reciprocably mounted in the cylinder bores 242 are the shoulder pistons 244 having upwardly-projecting piston rods 246 which with the cylinder bores 242 constitute lower punch-supporting reciprocatory hydraulic motors. The piston rods 246 have upper end surfaces 24% adapted to engage the bottom surface 250 of the outer lower punch 150. The latter is separated from the bottom surface 252 of the die 142 by a lower outer punch fill spacer or shoulder punch fill spacer 254. The fill spacer is of annular shape, resembling a large washer. Threaded into sockets 256 (FIGURE 1) in the bottom of the lower outer punch at equally-spaced locations near the periphery thereof are four headed retaining bolts or screws 258 (two only being shown), which pass downwardly through the suitably drilled cover plate 2:50 of the cylinder block 249 into similarly symmetrically-disposed bores 262 receiving the heads of the screws 258. Bolted or otherwise secured to the under side of the base plate 114 (FIGURES l, 5, 6 and 9) is an annular or cylindrical lower ram stop 264 having a lower end stop surface 266 engageable with the flanged or enlarged diameter portion 222 of the end wall 224 of the lower ram 226 in the raised position of the lower main piston 196 and lower ram 226 (FlGURE 1).

It will be understood that the various hydraulic cylinders are provided as usual with upper and lower service ports (not shown) connected to the hydraulic circuit whereby hydraulic pressure fluid may be fed into one service port and exhausted from the other service port to advance or retract its respective piston, as set forth below in the description of the operation of the invention.

Operation In the operation of the hydraulic briquetting press 19 of the present invention, let it be assumed that a pressing cycle has been completed, with the various moving parts of the press 159 in their relative positions shown in FIG- URE l and with the pressing of a flanged workpiece W completed, with the workpiece W ejected from the die cavity but not yet expelled from the die table 1%. As a consequence, FIGURE 1 shows the relative positions of the moving parts at the instant which marks the end of one pressing cycle and the beginning of the next pressing cycle. upper punch 62 attached to it are in their raised and retracted. or up position (FIGURE 1), the filling box or shoe 189 is in its rearwardly-retracted position (FIG- URE 2), and the top surfaces of the main die table 100 and die 142, lower outer punch 150 and lower inner punch 156 lie substantially in the same plane. Let it also be assumed that the hydro-electric operating circuit is in order with the pump (not shown) supplying oil or other hydraulic fluid under pressure to the various hydraulic cylinders set forth above and discussed individually below in, the order in which they take part in the operation. Let it also be assumed that the filling box 189 has been filled with a charge of suitable powdered material, metallic or non-metallic, such as powdered iron, powdered bronze or alloys thereof or the polyamide plastic commercially known as nylon.

Let it further be assumed that the various adjustments have been made for controlling the dimensions and density of the flanged workpiece W. In this respect, the lowermost position or down position of the upper ram 42 has been adjusted by turning the upper ram adjusting screw 34 (FIGURE 1) in one direction or the other until the upper ram 42 and upper punch 62 descend to the desired level. The uppermost position reached by the die table 1110 has also been adjusted by turning the cranks 80 (FIGURE 2) in one direction or the other so as to move the stop wedges 82 and 84 to such a location that their coacting stop blocks 94] and 92 are positioned at such a level as to engage the upper ends of the die table stop rods 98 when the die table 1% has risen to the desired uppermost level. The lowermost position to be attained by the die table has also been adjusted by rotating the die table lower. adjustable stop 130 (FIG URE 1) so as to rotate the externally-threaded sleeve 128 within the internally-threaded base ring 126 fixedly mounted on the base plate 114, thereby positioning the upper end surface 132 at the desired level. Finally, the lower main ram 226 has been adjusted for the proper depth of the die cavity 148 in its fill position (FIGURE 4) by turning the crank 220 (FIGURE 1) so as to rotate the flanged screw post 202 within the hollow main piston 196 through the intermediate rotation of the worm shaft 216, worm 214, worm wheel 212, pinion shaft 210, elongated pinion 206 and the toothed head or ring gear 294. During'the entire operation of the press 10, however, the upper-end surface 1&6 of the core rod 162. (FIGURES At such an instant, the upper ram 42 and the 4 and 7)' remains stationary at a fixed level because of its being fixedly and immovably mounted upon the base plate 114 (FIGURE 1) which in turn is fixedly mounted upon the struts 116, main cylinder 122 and press bed 14;

To initiate the pressing cycle, the operator presses the usual start button (not shown) controlling the electrohydraulic circuit including a series of limit switches, sequence valves, time delay relays, pressure relief valves and the like, whereupon the rotary motor 172, which may be either a hydraulic motor or a compressed air motor, rotates the feed gear 176 (FIGURE 2) which in turn advances the toothed feed rack 17% and filling shoe 189 from the retracted position of FIGURE 2 to the advanced position of FIGURE 3, whereupon the forward wall 186 of the filling shoe 18%. collides with and expels the workpiece W which had been pressed during the previous pressing cycle by pushing it off the die table 160 into a collection box (not shown).

Next, the hydraulic circuit supplies pressure fluid to the upper end of the main cylinder bore 124 and withdraws hydraulic fluid from the lower end, causing the main piston 196 to retract downward, consequently pulling the lower ram 226 and the cylinder block 240 downward to their lowermost or down positions. During this action, the pistons 244 in the circular cylinder block 240, which at all times during the operating cycle have a low standing hydraulic pressure beneath them in their respective cylinders 242, tend to move upward but are forcibly pulled.

downward away from the outer lower punch or shoulder punch 150 by the cover plate 269 of the cylinder block 240 (FIGURE 5). During this action, the shoulder punch or lower outer punch 150 is pulled downward toits down position by the engagement of the heads of the retaining screws 258 with the same cover plate 260 (FIG- URE 5). These actions establish the die cavity 148 so that it is open to its maximum extent and consequently becomes filled with powdered material dropping by gravity from the filling shoe 1% (FIGURE 4).

Next, the rotary fluid pressure motor 172 is reversed, causing reverse rotation of its pinion 176, with consequent retraction of the toothed rack 178 and filling shoe 180 from the filling position of FIGURE 4 to the retracted position of FIGURE 2. As the filling shoe 180 is thus retracted, it wipes or? any surplus powder from the top of the die cavity 148, leaving the charge or filP therein fiush 'with the top surface of the die 142.

Hydraulic pressure fluid is now fed to the upper end of the main upper cylinder bore 22 and exhausted from the lower end thereof so as to cause the upper piston 24 to advance or move downward, lowering the lower portion 66 of the upper ram 42 until the upper punch 62 enters the die cavity 148, compressing the charge of powdered material therein and forcing the die table to move downward until the die table engages the upper end 132 of the die table lower adjustable stop (FIGURE 6). The pre-set resistance to the downward advancement of the die table 10% is controlled by the counterpressure of the hydraulic fluid supplied to the lower ends of the die table cylinders 112 beneath their respective pistons 1 10;

Meanwhile, the downward travel of the die table 100 in this manner has consequently lowered the outer lower punch or-bottom punch 156 into contact with the upper ends 2480f theshoulder pistons 244. As a consequence, the retaining screws 258 connected to the lower outer punch have moved further downward in their bores ders 56 of the upper ram piston stops 50 (FIGURE 6). The powdered material in the die cavity 148 is now compacted or briquetted into a workpiece W, and ready for ejection from the die cavity 148.

Hydraulic pressure fluid is now introduced into the lower end of the upper main cylinder bore 22 beneath the piston head 26 of the upper piston 24, which is now in the position of FIGURE 6, while withdrawing hydraulic fluid from the upper end or" the cylinder bore 22, thereby causing the upper main piston 24 to move upward to its retracted position (FIGURE 9), carrying with it the upper ram 42 and the upper punch 62 to their raised and retracted positions of FIGURE 9. Hydraulic pressure fluid is now introduced into the lower ends of the die table piston cylinders 112, forcing the pistons 108 to move upward, carrying with them the die table 190 until the stop posts or rods 98 engage the adjustable stop blocks 98 and reach the positions shown in FIGURES 1 and 5. The die table 1% is now in its raised or up position.

While the die table 100 was rising in the abovedescribed manner, the outer lower punch or shoulder punch 150 carried upward thereby, moves upward out of contact with the upper end surfaces 243 of the piston rods 24-6 of the shoulder pistons 244 mounted in the cylinder bores 242 of the cylinder block 240 .(FIGURE 7), by reason of the fact that the piston heads 244 are at that time being held down by the cover plate 269 of the cylinder block 249. At the same time, the upward motion of the lower outer punch or shoulder punch 15%? has caused the lower end of the hub H of the workpiece W to move upward out of contact with the upper end surface 152 of the lower inner punch 156 (FIGURE 7). At this point of time, however, hydraulic pressure fluid is admitted to the lower end of the lower main cylinder bore 124 beneath the piston head 194 of its piston 196, and withdrawing hydraulic fluid from the upper end thereof, thereby moving the lower main piston 196 upward, carrying with it the lower main ram 225 and cylinder barrel 240 resting thereon, causing the'upper ends 248 of the shoulder pistons 244 to again engage the bottom surface 250 of the outer lower punch 15%] so that the lower inner punch 156 again engages the lower end of the hub H of the workpiece W (FIGURE 8). The shoulder pistons 244 are held in their raised positions by the standing hydraulic backup pressure beneath their piston heads, as explained above,

within their respective cylinder bores 242 in the cylinder block 240. This hydraulic fluid within the lower ends of the cylinder bores 242 is connected in the hydraulic circuit to a pressure relief valve (not shown) which is set to release hydraulic pressure fluid at a slightly higher pressure than the pressure required to strip or force upward the shoulder or flange portion F of the workpiece W out of the bore 146 in the die 142 constituting the upper outer portion of the die cavity 14%.

Meanwhile (FIGURE 9), the lower main piston 1%, lower main ram 226 and lower inner punch 155 continue to rise, together with the cylinder block 240 and the shoulder pistons 244 therein, held up by the standing hydraulic fluid pressure previously mentioned, thereby forcing the lower outer punch or shoulder punch 150 to rise, simultaneously with the lower inner punch 156, so that both simultaneously engage and push upward the flange F and hub H respectively of the workpiece W, ejecting the flwge or shoulder portion F of the workpiece W from the outer bore 145 of the die cavity 148. The upward travel of the lower outer punch or shoulder punch 15%; is now halted by the engagement of the lower outer punch fill spacer 254 with the bottom surface 252 of the die 142 (FIGURE 9). The shoulder pistons 244 in the cylinder bores 242 of the cylinder block 240 thus prevent it from further travel upward by the engagement of their top surfaces 248 with the bottom surface 250 of the lower outer punch 155) which has just been halted by the engagement of the spacer 254 with the bottom surface 252 of the die 1 .2 (FIGURE 9). The lower outer punch or 1Q shoulder punch 154 therefore, has now reached its up or raised position with its top surface 152 level or flush with the top surface 144 of the die 142.

At this time, however, the lower main piston 1%, lower main ram 226, cylinder block 240, cover plate 260 and lower inner punch 156 continue to move upward, overcoming the hydraulic fluid backup of standing pressure beneath the shoulder pistons 244 by reason of the overpowering pressure developed by the lower main piston 196 because of the greater hydraulic pressure in the lower end of its cylinder bore 124, forcing opening of the pressure relief valve which normally holds the pressure within the cylinder bores 242 of the shoulder piston 244 within the cylinder block 249 at a standing or backup pressure. As a result, the cylinder block 24% is forced upward relatively to the shoulder piston 244, consequently forcing the lower inner punch 156 to move upward until the flanged lower end or enlarged portion 222 of the lower ram 226 engages the annular depending lower end surface 266 of the lower ram stop 264 secured to and extending downwardly fiom the base plate 1%. Thereupon, the top surface 153 of the lower inner punch 155 reaches its up or maximum raised position flush or level with the top surfaces 144 and 152 of the die 142 and lower outer punch respectively (FIGURE 1),

thereby completely ejecting the workpiece W from the die cavity 14-8, completing the pressing cycle of the press 10. The workpiece W is now ready for expulsion from the top surface 99 of the die table 169 (FIGURE 1) by the subsequent advance of the filling shoe from its retracted position (FIGURE 2) to its forward position (FIGURE 4) at the start of the next pressing cycle, as set forth above at the beginning of the description of .the operation of the invention. The next pressing cycle is ready to begin when the various moving parts of the press 16 have reached their relative positions shown in FIGURE 1.

What I claim is: v

1. A hydraulic briquetting press for pressing externally flanged workpieces from powdered material, comprising a press frame having a lower presss bed and an upper press head, i

a die table reciprocably mounted on said press frame,

a die mounted on said die table and having a die bore therein,

a base member connected to said'press hame,

a reciprocatory hydraulic die table supporting motor mounted on said base member in yielding sustaining relationship with said die table,

a lower main ram, I

a lower outer punch-supporting reciprocatory hydraulic motor mounted on said lower main ram and re- I ciprocable relatively to said lower main ram,

a tubular lower outer punch mounted in said die bore and operatively connected to said punch-supporting motor,

a lower inner punch mounted on said lower main ram in telescoping relationship with said outer punch,

a lower main reciprocatory hydraulic motor mounted on said press bed in yielding supporting relationship with said lower main ram,

an upper main reciprocatory pressing motor reciprocably mounted on said press head,

and an upper pressing punch mounted on said upper pressing motor in telescoping relationship with said die bore.

2. A hydraulic briquetting press, according to claim 1, wherein a vertically-adjustable stop member is mounted on said base member beneath said die table in halting relationship with said die table, said stop member includes an annular threaded lower member disposed coaxial with said lower main hydraulic motor, and an annular oppositely-threaded upper member threadedly and rotatably engaging said lower member, said annular lower and upper members encircling said lower ram.

3. A hydraulic briquetting press, according to claim 1, wherein said lower reciprocatory hydraulic motor includes an internally-threaded hollow piston, an externally-threaded screw post threadedly engaging said piston, said post being mounted in supporting engagement with said lower main ram, and means for adjustably rotating said post relatively to said hollow piston.

4. A hydraulic briquetting press, according to claim 3, wherein said post-rotating means includes a gear mounted on said post, an elongated pinion meshing with said gear in relatively sliding driving engagement therewith, and means for rotating said pinion.

5. A hydraulic briquetting press, according to claim 4, wherein said pinion-rotating means includes a worm wheel connected to said pinion, a worm meshing with said worm wheel, and a rotary shaft operatively connected to said worm.

6. A hydraulic briquetting press, according to claim 1, wherein an upper ram is interposed between said upper motor and said upper punch and wherein an upper ram stop member is secured to said press head and depends therefrom into halting engagement with said upper ram.

7. A hydraulic briquetting press, according to claim 1, wherein said main upper motor includesa hollow internally-threaded piston, a threaded stem threadedly and rotatably mounted in said hollow piston and axially adjustably -movable relatively thereto, and an upper ram connected to said. stem and adapted to carry the upper punch. i

i 8. A hydraulic briquetting press, according to claim 7, wherein an upper ram stop member is secured to said press head and depends therefrom into halting engagement with said upper ram.

9. A hydraulic briquetting press, according to claim 1,

wherein said lower punch-supporting motor has a piston rod with an end'portion thereon separably engageable with the tubular outer punch.

10. A hydraulic briquetting press, according to claim 1, where n an elongated headed retaining member is wherein a lower punch-supporting motor support is 'mounted on said lower ram in supporting relationship with said lower punch-supporting motor and has a vertical bore reciprocably receiving the head of said retaining 4o adapted to be connected to the outer tubular punch and 12 a press frame having a lower press bed and an upper press head, a die table vertically reciprocably mounted on said press frame, means for vertically reciprocating said die table; an upper reciprocatory hydraulic pressing motor reciprocably mounted on said press head and having a pressing plunger movable toward and away fi om said die table, two pairs of upstanding stop-engaging members mounted on said press head in spaced parallel relationship, two pairs of stop wedges mounted on said press head for vertical motion relatively thereto and in alignment with said stop-engaging members,

each pair of said stop wedges having oppositelyinclined upper faces, two pairs of stop-operating wedges mounted on said press head for horizontal motion relatively thereto along parallel paths and having oppositely-inclined lower faces slidably engaging said upper faces,

the stop-operating wedges of each pair having oppositely-threaded substantially horizontal coaxial bores therethrough, means for yieldingly' urging said oppositely-inclined faces of each pair of said stop wedges into yielding engagement with said oppositely-incl ned faces of their respective stop-operating wedges, a pair of rotary screw shafts journalled on said press head in spaced parallel relationship,

each screw shaft having oppositely-threaded portions threadedly engaging the oppositely-threaded coaxial bores of its respective pair of stopoperating wedges, means drivingly interconnecting said screw shafts for synchronized rotation, I and means operatively connected to one of said screw shafts for rotating'said last-mentioned screw shaft.

References Cited in the file or this patent UNITED STATES PATENTS Wellnitz Jan. 20, 1942 2,270,829 2,338,491 Cutler Jan. 4, 1944 2,398,227 Hubbert Apr. 9, 1946 2,481,232 Moore Sept. 6, 1949 2,488,581 Cherry Nov. 22, 1949 2,509,783 Richardson May 30, 1950 2,762,078 Haller Sept. 11, 1956 2,831,230 Neth et al 'Apr. 22, 1958 2,855,628 Lassman Oct. 14, 1958 Ranch Aug. 8, 1961 

1. A HYDRAULIC BRIQUETTING PRESSING EXTERNALLY FLANGED WORKPIECES FROM POWDERED MATERIAL, COMPRISING A PRESS FRAME HAVING A LOWER PRESSBED AND AN UPPER PRESS HEAD, A DIE TABLE RECIPROCABLE MOUNTED ON SAID PRESS FRAME, A DIE MOUNTED ON SAID DIE TABLE AND HAVING A DIE BORE THEREIN, A BASE MEMBER CONNECTED TO SAID PRESS FRAME, A RECIPROCATORY HYDRAULIC DIE TABLE SUPPORTING MOTOR MOUNTED ON SAID BASE MEMBER IN YEILDING SUSTAINING RELATIONSHIP WITH SAID DIE TABLE, A LOWER MAIN RAM, A LOWER OUTER PUNCH-SUPPORTING RECIPROCATORY HYDRAULIC MOTOR MOUNTED ON SAID LOWER MAIN RAM AND RECIPROCABLE RELATIVELY TO SAID LOWER MAIN RAM, A TUBULAR LOWER OUTER PUNCH MOUNTED IN SAID DIE BORE AND OPERATIVELY CONNECTED TO SAID PUNCH-SUPPORTING MOTOR, A LOWER INNER PUNCH MOUNTED ON SAID LOWER MAIN RAM IN TELESCOPING RELATIONSHIP WITH SAID OUTER PUNCH, A LOWER MAIN RECIPROCATORY HYDRAULIC MOTOR MOUNTED ON SAID PRESS BED IN YIELDING SUPPORTING RELATIONSHIP WITH SAID LOWER MAIN RAM, AN UPPER MAIN RECIPROCATORY PRESSING MOTOR RECIPROCABLY MOUNTED ON SAID PRESS HEAD, AND AN UPPER PRESSING PUNCH MOUNTED ON SAID UPPER PRESSING MOTOR IN TELESCOPING RELATIONSHIP WITH SAID DIE BORE. 